From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vasily Averin Subject: [PATCH v6 16/16] memcg: enable accounting for ldt_struct objects Date: Mon, 26 Jul 2021 22:01:55 +0300 Message-ID: <765aa723-34f3-2b30-323a-b281ad32d5e4@virtuozzo.com> References: <9bf9d9bd-03b1-2adb-17b4-5d59a86a9394@virtuozzo.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=virtuozzo.com; s=relay; h=Content-Type:MIME-Version:Date:Message-ID:Subject :From; bh=QOm/SWMV/Asmk/Sj3wEkt1IsJkdhz+j421ZJ6yW2Ajw=; b=IvYBrKFsc8n6cSTBBlf WEDW0dZk1gvP67pT3J+ySKTvyxzpKi9mqoKizqq9iXQzbEcOlDju7o3q8EKdGuXByrf+r8EXpv3l+ 5GWiCL3yw1mCHuSM8A+JAjcFPPeXIJNEqo/DSHvUy7Y6GU0pGiQeBf+8Rft9GPj3fI00PefjF8E=; In-Reply-To: Content-Language: en-US List-ID: Content-Type: text/plain; charset="us-ascii" To: Andrew Morton Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Michal Hocko , Shakeel Butt , Johannes Weiner , Vladimir Davydov , Roman Gushchin , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Each task can request own LDT and force the kernel to allocate up to 64Kb memory per-mm. There are legitimate workloads with hundreds of processes and there can be hundreds of workloads running on large machines. The unaccounted memory can cause isolation issues between the workloads particularly on highly utilized machines. It makes sense to account for this objects to restrict the host's memory consumption from inside the memcg-limited container. Signed-off-by: Vasily Averin Acked-by: Borislav Petkov --- arch/x86/kernel/ldt.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c index aa15132..525876e 100644 --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -154,7 +154,7 @@ static struct ldt_struct *alloc_ldt_struct(unsigned int num_entries) if (num_entries > LDT_ENTRIES) return NULL; - new_ldt = kmalloc(sizeof(struct ldt_struct), GFP_KERNEL); + new_ldt = kmalloc(sizeof(struct ldt_struct), GFP_KERNEL_ACCOUNT); if (!new_ldt) return NULL; @@ -168,9 +168,9 @@ static struct ldt_struct *alloc_ldt_struct(unsigned int num_entries) * than PAGE_SIZE. */ if (alloc_size > PAGE_SIZE) - new_ldt->entries = vzalloc(alloc_size); + new_ldt->entries = __vmalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_ZERO); else - new_ldt->entries = (void *)get_zeroed_page(GFP_KERNEL); + new_ldt->entries = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); if (!new_ldt->entries) { kfree(new_ldt); -- 1.8.3.1